How to Hide a Septic Tank Riser or Cap

Homeowners, are you tired of looking at the top of that ugly septic tank each and every day? Whether it be a concrete riser or one of the newer plastic dome style caps, you can learn to cover it up by following these easy steps.


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    Grab a measuring tape or ruler and head outside to where the septic tank is. You're going to take two quick measurements here. Real fast and easy so don't worry if you're not Joe Handyman with measurements!
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    Measure the height of the tank. Place the end of the tape on the ground where the septic tank goes underground. You want an accurate reading on the total height of the riser. So your measuring from the ground, up to the very top of the tank.
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    Log the diameter of the tank. To do this simply stand over the tank, flop the tape measure down and measure the line directly down the center of the circle. Just a diagonal measure across the top, not the circumference, which is the distance around the outer edge (we don't care about that).
    • If there's a square box on one side of the tank, that's a junction box. It's best to measure the diameter of the tank including and not including that box. Not all tanks have these junction boxes.
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    Measure and record your measurements carefully! No shooting from the hip and there's no need to "add a couple inches" just to be safe. We don't want that. We need accurate measurements here.
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    Choose a correctly sized fake rock. Fake rocks come in a variety of different sizes and shapes. When selecting one, it's important that you heed the usable interior dimensions. The trouble is these can be somewhat confusing, especially when in chart format.
    • Check out the sources and citations section for some links to online forms where you can enter dimensions and receive suggestions on fake rock models which will work well for your specific application.
    • Don't forget to consider having vents placed in the rock if the septic cap you are covering has vents in it.
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    Put that cover to good use. Flip it over and cross your fingers that you measured well! Don't forget to pound in the ground stakes if the rock came with them. Most do.
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    Adjust for appearance, plan for access. Take a few steps back and survey the scene. Does the rock look natural as is or should you improve it with some mulch, shrubs, flowers and edging? You can make a landscaped area with the fake rock as the center piece or just leave it as good enough. Be proud you no longer have to look at that ugly septic tank rise anymore. Whatever you decide, there will be a need to use that cover again. Allow for hose access around any plantings. Plant things far enough away that they won't obstruct access when full grown.


  • Remember, when selecting a fake rock always consult the interior dimension charts to make sure the rock is large enough to cover.
  • Don't forget the vents! If the septic tank in your yard is vented it's a good idea to have the rock ventilated as well.
  • Don't forget to use ground stakes! The wind can lift these fake rocks up, up and away!

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Categories: Plumbing Drains Waste and Vents